Conventionally, there have been known light source devices including light emitting elements for emitting exciting light, and a fluorescent element for converting the exciting light emitted from the light emitting elements into fluorescence and for reflecting the fluorescence (for example, Patent Document 1). In such light source devices, the light emitting elements generate heat when emitting light, and the fluorescent element generates heat when converting exciting light into fluorescence. For coping therewith, in the light source device according to Patent Document 1, it is necessary to provide means for cooling the light emitting elements, and means for cooling the fluorescent element, separately from each other.